Polyethylene glycol treated carbon black and compounds thereof

ABSTRACT

A treated carbon black may be produced by treating carbon black with at least one polyethylene glycol having a molecular weight of from about 1,000 to about 1,000,000. The treated carbon black may be used in forming polymeric compositions, such as semi-conductive and insulating compounds, for example for use in electrical cables.

This is a Division of application Ser. No. 08/504,789 filed Jul. 20,1995 now U.S. Pat. No. 5,725,650, which in turn is a Division ofapplication Ser. No. 08/406,525 filed Mar. 20, 1995 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to treated carbon black, suitable for use assemi-conductive compositions such as in electrical cables. Moreparticularly, the present invention relates to carbon black treated witha polyethylene glycol, also known as a homopolymer of ethylene oxide,and to semi-conductive compositions including, for example, a polyolefinand the treated carbon black. Such treated carbon blacks arefree-flowing, produce low dust levels, are attrition-resistant, areeasily dispersible in polymeric systems and provide enhancedrheological, mechanical and electrical properties. The present inventionalso relates to a process for producing such treated carbon blacks, andcompositions produced therefrom.

Any of a wide variety of carbon blacks may be used in the presentinvention. Thus the term carbon black is used herein in its genericsense to include types of finely divided carbon such as lamp black,channel black, furnace black, acetylene black and the like. Preferably,the carbon black is in the fluffy form. Although the carbon blacks areeasily dispersed in liquid and polymeric systems in their fluffy forms,they are extremely difficult to handle with respect to conveying andaccurate weighing. This is particularly due to their low bulk densitiesand generally high dust levels, which tend to lead to compaction andconsequent irregular feed in continuous compounding operations. Sucheffects are undesirable because, for example, continuous compoundingoperations are desirable for wire and cable compounds as a means toensure uniformity and cleanliness of the compounds.

A persistent problem with carbon black has been the relative difficultyand inconvenience associated with manufacturing, transporting and usingthe carbon black. When the carbon black is packaged, transported andremoved from its packaging, carbon black dust is produced.

To improve the handling characteristics of the fluffy carbon blacks,they are generally agglomerated by various mechanical processes toproduce pellets, either in the dry state or with the aid of a liquidpelletizing aid. Generally the carbon black particles are held togetherby weak forces. The most common process is to pelletize the fluffycarbon blacks using a liquid pelletizing aid such as oil or water.However, the agglomeration or densification process has been found tohave a detrimental effect on the dispersion characteristics of thefluffy carbon blacks. That is, as the fluffy carbon blacks areagglomerated into pellets, they become less easily dispersible inpolymeric systems. Therefore, there exists a tradeoff between acceptablehandling characteristics and ease of dispersion.

In order to compound well dispersed formulations with these carbonblacks, they are often pelletized with materials such as sodium lignosulfonate, water, sucrose, etc., as described below. However, thepelletizing aids often produce less than adequate results, or result inthe carbon black being incompatible with the formulation in which it isto be combined. For example, some carbon blacks do not develop adequatepellet strength when pelletized with water. This is due to the very lowvan der Waals forces existing between the carbon structure. Thus,although in pellet form, they are quite friable and result in high dustlevels. The result is inconsistent feed and consequent inhomogeneousdispersion in a compound.

Processes for pelletizing carbon blacks to produce carbon black pelletsare known in the art. For example, U.S. Pat. No. 2,065,371 to Glaxnerdescribes a wet pelletization process whereby the fluffy carbon blackand a liquid such as water are combined and agitated until sphericalcarbon black beads are formed. The beads are then dried to reduce thewater content to below 1% to form carbon black pellets.

In addition to water, a wide variety of binder additives are known to beuseful in the wet pelletization process to further improve the pellethandling characteristics of the fluffy carbon blacks. For example, thefollowing references describe the use of various binder additives aspelletizing aids for producing carbon blacks: U.S. Pat. No. 2,427,238 toSwart describes the use of a number of hygroscopic organic liquids orsolutions, including ethylene glycol, in the compounding of rubber-likematerials. U.S. Pat. No. 2,850,403 to Day discloses the use ofcarbohydrates such as sugar, molasses, soluble starches, saccharides andlignin derivatives as pelletization binder additives in the range of0.1% to 0.4% by weight of the dry carbon black. The wet pellets are thendried for a given residence time at a temperature of from 150° C. to425° C. to carbonize the carbohydrate binder. U.S. Pat. No. 2,908,586 toBraendle et al. discloses the use of a rosin emulsion as an alternativeto the carbohydrates, in a preferred amount of from 0.5% to 2.0% byweight of the dry carbon black. U.S. Pat. No. 2,639,225 to Venutodiscloses the use of sulfonate and sulfate anionic surfactants aspelletizing aids in an amount of 0.1% to 0.5% by weight of the drycarbon black. U.S. Pat. No. 3,565,658 to Frazier et al. discloses theuse of a fatty amine ethoxylate nonionic surfactant as a pelletizing aidwherein the fatty amine ethoxylate has a level of ethoxylation in therange of from 2 to 50 moles of ethylene oxide per fatty amine group. Thenonionic surfactant is disclosed as preferably being present in therange of 0.05% to 5.0%. Similarly, U.S. Pat. No. 3,645,765 also toFrazier et al. discloses the use of a fatty acid or rosin acidethoxylate nonionic surfactant in the range of 0.1% to 10.0% by weightof the carbon black. The nonionic surfactant is disclosed as having alevel of ethoxylation of from 5.0 to 15.0 moles of ethylene per acidgroup. Soviet Union Patent Publication No. 937,492 discloses the use ofa 0.1% to 5.0% aqueous solution of a reaction product of urea and anethoxylated alkylolamide, where the level of ethoxylation is from 1.0 to7.0 moles of ethylene oxide per alkylolamide. Finally, U.S. Pat. No.3,844,809 to Murray discloses the use of a nonionic surfactantcontaining randomly repeating poly(ethylene oxide) and poly(dimethylsilicone) groups. The reference discloses that 0.4% to 2.5% of anaqueous solution containing 0.001% to 0.1% of the nonionic surfactantresults in a reduction in pellet dust levels. Molasses is also includedat substantially higher concentrations of up to 2.0% as a co-binder, andnitric acid is included in an amount of up to 15.0% as an oxidizingsource. The above patents disclose improved pellet handling qualities,but do not disclose changes in the performance properties of thepelletized carbon black in final product applications.

Among the handling characteristics of the carbon black that may beimproved by binder additives and the level of such additives being usedin the pelletizing process are such characteristics as adhesion,dispersibility, dispersion rate, viscosity stability and anti-staticproperties. For example, Japanese Patent Publication No. 01-201,369discloses the use of a carboxylic acid type amphoteric surfactant in aconcentration of from 0.001% to 0.1% in the pelletizing water to producecarbon black pellets with low adhesion and excellent dispersibility.U.S. Pat. No. 3,014,810 to Dybalski et al. discloses the benefits of wetpelletizing a range of pigments, including carbon black, with 0.05% to5% by weight of a blend of a quaternary ammonium compound and abis(2-hydroxyethyl)alkyl amine. The disclosed benefits includeimprovements in dispersion rate, viscosity stability and anti-staticproperties.

As described above, oil has also been used, with or without theinclusion of water, as a pelletizing aid. For example, U.S. Pat. Nos.2,635,057 to Jordan, 3,011,902 to Jordan and 4,102,967 to Vanderveen etal. disclose the use of oil, such as mineral oil, in the pelletizingprocess to improve the handling characteristics of carbon black pellets.Additionally, the use of polymers in an emulsion, organic solvent,solution or molten form has been disclosed as a means of modifying thepellet properties of carbon black, for example as described in U.S. Pat.Nos. 2,511,901 to Bunn (latex emulsions), 2,457,962 to Whaley (aqueousemulsions or dispersions of rubber), 4,440,807 to Gunnell (molten rubberor a solution or emulsion of rubber), 4,569,834 to West et al. (emulsionof an oxidized polyethylene) and 5,168,012 to Watson et al. (a rubberlatex) and in Japanese Patent Publication No. 77-130,481.

Other alternative pelletizing aids for producing carbon black pelletsinclude sodium ligno sulfonates, silanes, sucrose, and nonionicdispersants such as alkyl succinimides and alkylated succinic esters.However, such alternatives have not produced favorable carbon blackpellets and/or polymer compositions. For example, carbon blacks producedusing sodium ligno sulfonates are generally considered unsuitable foruse in semi-conductive polymer compositions due to the increasedpropensity for water tree formation resulting from the increased sulfurcontent. Other drawbacks of the alternative pelletizing aids includeadhesion of the carbon blacks to processing equipment, difficulty inapplying the pelletizing aids to the carbon blacks, and (particularly inwire and cable formulations) water tree formation in the polymercompositions.

The use of polyethylene glycol in the production of rubber andthermoplastic resin materials is also generally known. For example, U.S.Pat. No. 4,230,501 to Howard et al. describes the use of polyethyleneglycol in a pigment concentrate that is easily dispersed in plastics.The polyethylene glycol or a hydrocarbon resin is incorporated as aviscosity control additive in a natural, petroleum or synthetic wax,which is then mixed with 51% to 85% by weight of a pigment to form apigment concentrate. U.S. Pat. No. 4,397,652 to Neumann discloses theproduction of powdered compositions containing organic dyes and opticalbrighteners, that produce no negligible dust levels. Polyethylene glycolis disclosed both as an adhesive component, at molecular weights greaterthan 3,000, and as a dust-binding agent, at molecular weights between200 and 1,000. British Patent Specification No. GB 975,847 discloses theuse of an aqueous solution of polyethylene glycol or an aliphaticderivative as a means of producing agglomerates of organic rubberchemicals. Pellets of the composition are formed via an extrusionprocess, and subsequently dried at low temperatures.

Polyethylene glycol is also known in the art as an additive for directcompounding into crosslinked and thermoplastic resin compositions. Forexample, U.S. Pat. No. 4,013,622 to DeJuneas et al. describes theincorporation of 100 to 600 ppm of polyethylene glycol having amolecular weight of from 600 to 20,000 into a major amount of lowdensity polyethylene. The polyethylene glycol is incorporated into thethermoplastic resin to reduce the breakdown of the polyethylene duringblown film operations. As a further example, U.S. Pat. No. 3,361,702 toWartman et al. discloses the use of polyethylene glycol or branchedethoxylate molecules as plasticizers for ethylene-acrylic acidco-polymers.

Polyethylene glycol is also known to be useful in the production ofpolymer compositions. For example, U.S. Pat. Nos. 4,812,505 to Topcik,4,440,671 to Turbett and 4,305,849 to Kawasaki et al. disclose the useof polyethylene glycol, having a molecular weight of from 1,000 to20,000, for reducing the water treeing characteristics in polymercompositions for electrical insulation materials. U.S. Pat. No.4,812,505 to Topcik discloses incorporating from 0.1 to 20% by weight ofpolyethylene glycol into a polymer composition. U.S. Pat. No. 4,440,671to Turbett discloses the incorporation of from about 0.2 to about 1 partof polyethylene glycol, having a molecular weight of from 1,000 to20,000, per part by weight of diphenyl amine. U.S. Pat. No. 4,305,849 toKawasaki et al. discloses the incorporation of between 0.3% and 10% byweight of polyethylene glycol directly into an insulating polymercomposition by kneading the polyethylene glycol with the polymer.

In this respect, water treeing refers to a phenomenon that occurs when apolymeric insulation material such as polyolefin is subjected to anelectrical field over a long period of time in an environment containingwater. This phenomenon is to be distinguished from electrical trees(carbonization of the insulation material due to electrical discharges)and chemical trees (crystals formed from reactive gases on the conductorsurface).

The reduction of the water treeing phenomenon is also addressed in U.S.Pat. No. 4,612,139 to Kawasaki et al., which is directed to reducing thewater treeing problem in semi-conductive polymer compositions containingcarbon black. The patent discloses that polyethylene glycol can bedirectly incorporated into a semi-conductive polymer composition toeliminate the water treeing phenomenon. Polyethylene glycol, having amolecular weight of from 1,000 to 20,000, is incorporated into thepolymer in an amount of from 0.1% to 20% by weight of the polymer.Similar compositions are disclosed in German Patent No. DE 27 23 488.The German patent discloses that polyethylene glycol and other mobileadditives are beneficial in reducing the interlaminar adhesion betweenthe insulation layer and the outer conductive layer (e.g., theinsulation shield) in an electrical cable construction.

Japanese Patent Publications Nos. 61-181,859 and 61-181,860 discloseelectroconductive compositions. The compositions comprise a crystallinepolyalkylene oxide and carbon black or graphite. 61-181,859 alsodiscloses that the polymer is modified to contain carboxyl or carboxylicacid side chains.

SUMMARY OF THE INVENTION

The need continues to exist for improved pelletizing aids for use in theproduction of carbon black pellets wherein both the handlingcharacteristics of the pellets and the performance characteristics ofthe polymer compositions in which the pellets are incorporated areimproved. We have discovered that treating carbon black, preferably influffy form, with a polyethylene glycol compound as a pelletizing aidproduces treated carbon black pellets having such improved handling andperformance characteristics.

The need also continues to exist for improved compositions for theproduction of such articles as electrical wire and cable. Specifically,the need continues to exist for materials with improved performancecharacteristics. We have discovered that the aforementioned treatedcarbon black may be used to produce polymer compositions, such assemi-conductive and insulating polyolefin compositions, having suchimproved performance characteristics.

Such improved treated carbon black and polymer compositions containingthe treated carbon black with unique and novel properties, and processesfor producing same, are provided herein.

Specifically, the present invention provides polymer compositions, suchas a semi-conductive composition comprising a polyolefin homopolymer,copolymer or terpolymer and a carbon black treated with at least onepolyethylene glycol having a molecular weight of from about 1,000 toabout 1,000,000. As used herein, "molecular weight" refers to weightaverage molecular weight (Mw).

The present invention also provides pelletized carbon black wherein thecarbon black pellets comprise carbon black treated with at least onepolyethylene glycol having a molecular weight of from about 1,000 toabout 1,000,000.

The present invention further provides a process for preparing suchcarbon black pellets, comprising treating a carbon black with at leastone polyethylene glycol having a molecular weight of from about 1,000 toabout 1,000,000, to produce the treated carbon black.

Polymer compositions incorporating the treated carbon blacks of thepresent invention may, for example, be used as semi-conductive layersbonded to primary insulation layers or electrical conductors, such as inelectrical cables. For example, the polymer compositions may be used asinsulation shield materials in the form of semi-conductive layers thatmay be easily stripped or removed from the insulation materials. Thesecarbon blacks may also be used in strand filling compounds, eitherconductive or nonconductive, or in conductive or nonconductive cablejacketing formulations. Furthermore, these treated carbon blacks may beincorporated in minor amounts, without imparting semi-conductiveproperties to the composition, for example as a colorant in insulatingcompounds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a typical power cable.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Any of a wide variety of carbon blacks may be used in the presentinvention, including finely divided carbon such as lamp black, furnaceblack, and the like. Preferably, the carbon black is in the fluffy form.

In the process of the present invention, the carbon black, preferably influffy form, is treated with a polyethylene glycol having a molecularweight of from about 1,000 to about 1,000,000. In the presentspecification, the polyethylene glycol is referred to generally as a"polyethylene glycol compound" or simply as "polyethylene glycol."However, it is understood that the terminology also includes thosepolyethylene glycol compounds that are also referred to as homopolymersof ethylene oxide, and includes such compounds as result fromcondensation polymerization of ethylene glycol and additionpolymerization of ethylene oxide. The term polyethylene glycol compoundsthus encompasses those polymers having the repeating unit (CH₂ CH₂O)_(n). The polyethylene glycol compound may be added onto the carbonblack as a pelletizing aid during formation of the carbon black pellets.

In the present invention, it is preferred that the polyethylene glycolhave a molecular weight of from about 1,000 to about 1,000,000. Morepreferably, the polyethylene glycol has a molecular weight of from about20,000 (preferably greater than 20,000) to about 1,000,000 and even morepreferably from about 35,000 to about 100,000.

In the present invention, it is preferred that the polyethylene glycolcompound be present in an amount of from about 0.1% to about 50% byweight of the carbon black. That is, with the polyethylene glycolcompound being used as a pelletizing aid on the carbon black pellets, itis preferred that the polyethylene glycol compound be present in thetreated carbon black in an amount of from about 0.1% to about 50% byweight. More preferably, the polyethylene glycol compound may be presentin an amount of from about 0.1% to about 20%, and even more preferablyin an amount of from about 1% to about 10% by weight of carbon black.

In preparing the treated carbon blacks, it may be preferable to form asolution containing the polyethylene glycol compound. If a solution ofthe polyethylene glycol compound is used, the solvent may be any of awide variety of solvents capable of dissolving the polyethylene glycolcompound. For example, the polyethylene glycol compound may be readilydissolved in water and/or a variety of organic solvents including, butnot limited to, methanol, ethanol, isopropanol, carbon tetrachloride,trichloroethylene, benzene, toluene, xylene, acetone, mixtures thereofand the like. As to the solvent, it is more important that thepolyethylene glycol compound be homogeneously dispersed or dissolved inthe solvent, but the exact solvent utilized is generally not crucial.Preferably, however, the polyethylene glycol compound is used in anaqueous solution, especially as the molecular weight of the polyethyleneglycol compound increases. On the basis of the instant disclosure, oneskilled in the art will be able to readily select an appropriate solventfor the specific application.

Alternatively, the polyethylene glycol compound may be heated to atemperature above the melting point of the compound where the viscosityof the molten compound is such as to facilitate a spray application ontothe carbon black. Here it is noted that many of the polyethylene glycolcompounds are soluble in water at room temperature, and therefore littleor no heating may be required. The viscosity of the molten compound,although not being limiting, is preferably below about 10 Poise. Thetemperature of the carbon black and the polyethylene glycol compoundshould be maintained above the melting point of the compound forsufficient time to allow for homogeneous mixing.

In embodiments of the present invention, the polyethylene glycolcompound is used as a pelletizing aid to form carbon black pellets fromthe carbon blacks. The pelletization process generally comprisescontacting the carbon black with a solution containing the polyethyleneglycol compound and optionally selectively heating and drying the carbonblack pellets.

The carbon black may be contacted with the polyethylene glycol compoundby introducing the carbon blacks into a pelletizer apparatus with thepolyethylene glycol compound. For example, the carbon black, preferablyin fluffy form, may be introduced into the pelletizer with a solution ofthe polyethylene glycol compound. Examples of such pelletizing apparatusare known in the art, and include pin pelletizers. When the polyethyleneglycol compound is introduced into the pelletizer apparatus in the formof a solution, for example in any of the above-described solvents, theconcentration of the polyethylene glycol compound in the solvent ispreferably in the range of from about 0.5% to about 35% by weight.However, the concentration of polyethylene glycol compound in thesolvent, and the relative amount of solvent to carbon black, should beadjusted to ensure that the appropriate amount of polyethylene glycolcompound is present on the carbon black particles, as described above.

After the carbon black has been contacted with the polyethylene glycolcompound, the resultant wet carbon black pellets may optionally beheated at a controlled temperature and for a controlled length of timeand/or at a reduced pressure to dry the pellets.

The treated carbon black of the present invention may be used to form awide variety of compositions. For example, the treated carbon black maybe used in forming pigment materials or may be combined with polymersand other optional components to form semi-conductive and insulatingcompositions, such as for use in electrical cables and electricalshielding. The semi-conductive compositions may be made by combining apolymer with an amount of carbon black sufficient to render thecompositions semi-conductive. Similarly, the insulating materials may beformed by incorporating minor amounts of carbon black, for example as acolorant, into a polymer composition. Such insulating materials may beformed by combining a polymer and an amount of carbon black much lessthan that sufficient to impart semi-conductive properties to thematerial.

Specifically, the polymeric compositions in embodiments of the presentinvention may be made by combining a polymer such as a polyolefin withan amount of carbon black sufficient to render the compositionssemi-conductive.

In preparing the polymer compositions of the present invention, thepolymer may be selected from any of the various homopolymers, copolymersand terpolymers known in the art, the selection being based upon theultimate desired use of the polymer composition. For example, thepolymers used in the polymeric compositions of the present invention mayinclude, but are not limited to, homopolymers, copolymers and graftpolymers of ethylene where the co-monomers are selected from butene,hexene, propene, octene, vinyl acetate, acrylic acid, methacrylic acid,esters of acrylic acid, esters of methacrylic acid, maleic anhydride,half esters of maleic anhydride, carbon monoxide and the like;elastomers selected from natural rubber, polybutadiene, polyisoprene,random styrene butadiene rubber, polychloroprene, nitrile rubbers,ethylene propylene copolymers and terpolymers and the like; homopolymersand copolymers of styrene, including styrene-butadiene,styrene-butadiene-styrene linear and radial polymers,acrylonitrile-butadiene-styrene, styrene acrylonitrile and the like;linear and branched polyether or polyester polyols; crystalline andamorphous polyesters and polyamides; alkyd resins, rosin acids or rosinesters; hydrocarbon resins produced from thermal or Friedal Craftspolymerization of cyclic diene monomers such as dicyclopentadiene,indene, cumene and the like; ethylene/silane copolymers;ethylene/α-olefin/diene terpolymers such asethylene/propylene/1,4-hexadiene, ethylene/1-butene/1,4-hexadiene andthe like; and hydrocarbon oils such as paraffinnic oil, naphthalenicoil, hydrogenated naphthenic oil and the like; mixtures thereof and thelike. Additionally, the polymer used in compositions of the presentinvention may include copolymers and terpolymers containing theabove-identified polymers as major components of the copolymer orterpolymer.

Preferably, the polymer used in the compositions of the presentinvention includes ethylene-vinyl acetate, ethylene butene such asethylene/1-butene, ethylene octene, ethylene ethyl acrylate, ethyleneacrylic acid, equivalents thereto, mixtures thereof and the like.

The precise monomer content of the polymers used in the presentinvention will depend upon such factors as economic considerations andthe desired applications of the resultant composition. In the case ofusing a polyolefin in forming the polymeric composition, typically thepolymers used in compositions of the present invention will generallycomprise in the range of from about 25 mole percent to about 98 molepercent ethylene, based on the total moles of monomer. Preferably, thepolyolefin polymers comprise from about 30 mole percent to about 95 molepercent, and more preferably from about 35 mole percent to about 90 molepercent, ethylene. The other monomers, in the case of polyolefincopolymers, will comprise the balance of the polymer.

However, the ethylene content in the polymers may vary depending on thecomonomer(s) present in the polymer. For example, in the case of anethylene/vinyl acetate copolymer, it is preferred that the polymercomprise from about 15 mole percent to about 80 mole percent vinylacetate. Preferably, the ethylene/vinyl acetate copolymer is of therubbery variety, and accordingly has a vinyl acetate content of aboveabout 28 mole percent. Even more preferably, the ethylene/vinyl acetatecopolymer comprises from about 40 mole percent to about 60 mole percentvinyl acetate.

Additionally, the polymer, copolymer or terpolymer used in the polymericformulations of the present invention may be either crosslinked ornon-crosslinked. If the polymer is to be crosslinked, any of a widevariety of crosslinking agents such as those known in the art may beadded to the formulation.

For example, a typical formulation of a polymeric composition for use insemi-conductive wire and cable applications of the present inventionpreferably comprises:

25-55% by weight of a carbon black treated with 0.5 to 10 parts of apolyethylene glycol per 100 parts of carbon black;

0-2% by weight of a stabilizer or antioxidant;

0-5% by weight of an organic peroxide, such as dicumyl peroxide;

0-10% by weight of a vinyl silane; and

the remainder being a polymer or a blend of polymers.

The formulation may also include an additive polymer such as, forexample, acrylonitrile butadiene elastomer containing, for example,25-55% by weight acrylonitrile.

In the compositions of the present invention, the treated carbon blackis generally present in the composition in the amount of from about 0.1to about 65% by weight, and preferably from about 10 to about 50% byweight, based on the weight of the total composition. Such compositionsgenerally possess semi-conductive properties. The content of the treatedcarbon black may be adjusted, of course, according to the desired use ofthe final composition and the desired relative conductivity of thecomposition. For example, carbon black may be incorporated into apolymer composition in smaller amounts to provide colored insulatingmaterials or to improve the ultra-violet resistance of the compounds.

The compositions of the present invention may also include suitableadditives for their known purposes and in known and effective amounts.For example, the compositions of the present invention may also includesuch additives as crosslinking agents, vulcanizing agents, stabilizers,pigments, dyes, colorants, metal deactivators, oil extenders,lubricants, inorganic fillers and the like.

For example, the polymer compositions of the present invention mayinclude at least one crosslinking agent, preferably in an amount of fromabout 0.5 to about 5% by weight, based on the weight of the specificpolymer being used. An organic peroxide is preferably used as a freeradical generator and crosslinking agent. Useful organic peroxidecrosslinking agents include, but are not limited to,α,α'-bis(tert-butylperoxy)-diisopropylbenzene, dicumyl peroxide,di(tert-butyl) peroxide, and2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane. Various other knowncoagents and crosslinking agents may also be used. For example, organicperoxide crosslinking agents are disclosed in U.S. Pat. No. 3,296,189,the entire disclosure of which is incorporated herein by reference.

As examples of antioxidants and processing aids that may be incorporatedin the polymer compositions of the present invention, may be mentioned,for example, polymerized 1,2-dihydro-2,2,4-trimethylquinoline, octadecyl3,5-ditert-butyl-4-hydroxyhydrocinnamate,4,4'-thio-bis-(3-methyl-6-tert-butylphenol),thio-diethylene-bis-(3,5-ditert-butyl-4-hydroxy) hydrocinnamate,distearyl-thio-diproprionate, mixtures thereof and the like. Suchantioxidants may be present in compositions of the present invention inan amount of preferably from about 0.4 to about 2.0% by weight, and morepreferably from about 0.4 to about 0.75% by weight. Other suitableconventional antioxidants that may be used in compositions of thepresent invention include sterically hindered phenols, phosphites andselected amines.

Additionally, processing aids may be added to the polymeric formulationsfor their known purposes. Thus, although processing aids are notnecessary to achieve homogeneous blends and reduced viscosity, they maybe added into the compositions of the present invention to furtherenhance these properties. For example, the processing aids may include,but are not limited to, metal stearates such as zinc stearate andaluminum stearate, stearate salts, stearic acid, polysiloxanes,stearamide, ethylene-bisoleyamide, ethylene-bisstearamide, mixturesthereof and the like. Processing aids, when incorporated intocompositions of the present invention, are generally used in amounts offrom about 0.1 to about 5.0 percent by weight, based on the total weightof the polymer composition.

The polymer compositions of the present invention may be manufacturedusing conventional machinery and methods to produce the desired finalpolymer product. The compositions may be prepared by batch or continuousmixing processes such as those well known in the art. For example,equipment such as Banbury mixers, Buss co-kneaders, and twin screwextruders may be used to mix the ingredients of the formulation. Forinstance, the components of the polymer compositions of the presentinvention may be mixed and formed into pellets for future use inmanufacturing such materials as insulated electrical conductors.

The polymer compositions of the present invention may be incorporatedinto any product where the properties of the polymer composition aresuitable. For example, the polymer compositions are particularly usefulfor making insulated electrical conductors, such as electrical wires andpower cables. Depending on the conductivity of the polymer composition,the polymer composition may be used, for example, as a semi-conductivematerial or as an insulating material in such wires and cables. Morepreferably, a semi-conductive shield of the polymer composition may beformed directly over an inner electrical conductor as a conductorshield, or over an insulating material as a bonded or strippableinsulation shield or as an outer jacketing material. These carbon blacksin selected polymer compositions may also be used in strandfillingapplications in either conductive or nonconductive formulations.

For ease of illustration, FIG. 1 depicts the typical components of anelectrical cable. FIG. 1 shows a typical power cable comprising aconductive core (such as a multiplicity of conductive wires), surroundedby several protective layers. Additionally, the conductive core maycontain a strandfiller with the conductive wires, such as a waterblocking compound. The protective layers include a jacket layer,insulating layer, and semi-conductive shields.

When polyethylene glycol is used to treat the carbon blacks, a polymericcomposition containing these treated carbon blacks exhibits propertiesthat are unique and different from those observed when the polyethyleneglycol is mixed directly into the polymeric composition. For example, ina polymeric formulation comprising a carbon black treated withpolyethylene glycol, as compared to a polymeric formulation comprising acarbon black and polyethylene glycol mixed directly into theformulation, the differences described below may be observed. Here,these differences are noted for a polymeric composition comprising atleast one polyolefin resin, an antioxidant, a curative agent, carbonblack, and a polyethylene glycol compound either as an additive or as atreating compound for the carbon black.

Directly adding the polyethylene glycol compound to a polymericformulation decreases the time to 50% cure and 90% cure (t_(c) (50) andt_(c) (90), respectively). Furthermore, direct addition of thepolyethylene glycol compound depresses the scorch time (t_(s) 2) of thepolymeric composition. Increasing the ratio of the polyethylene glycolcompound additive further deteriorates these results. However, thesechanges are not observed in a polymeric composition comprising carbonblack treated with the polyethylene glycol compound. The increased curetimes and scorch time are preferable, for example, to prevent theproduct from scorching and curing prematurely and thus clogging theprocessing equipment or decreasing the output rates.

The volume resistivity of the polymeric compositions may also beunexpectedly affected by the use of the polyethylene glycol compound asa treating compound for carbon black. Specifically, there is aninteraction of level of addition of the polyethylene glycol compounds ascarbon black pellet aids. Increasing the level of polyethylene glycolcompound in the treated carbon black significantly increases the volumeresistivity of the polymeric composition over a broad temperature rangein some polymeric systems, while decreasing the volume resistivity inother polymeric systems. Thus the volume resistivity effect isresin-dependent. Increasing the level of the polyethylene glycolcompound used as a carbon black treating aid further enhances theseresults.

Use of the treated carbon blacks also affects the extruder viscosityduring processing of the polymeric compositions. For example, use of thetreated carbon blacks in high viscosity polymeric compositionssignificantly decreases the viscosity of the compositions, whilemaintaining output levels. Furthermore, as the shear rate is increasedduring processing, increased levels of the polyethylene glycol compoundin the treated carbon blacks further decreases the viscosity whilemaintaining output levels. These results are superior to the resultsobtained by directly adding the polyethylene glycol compound to theformulation because decreased viscosity allows for increased output orconstant output at decreased shear rates.

Moreover, the use of the polyethylene glycol compound as a treatingcompound for the carbon black is observed to significantly decreaseadhesion of the polymeric composition to crosslinked polyethylene. Thisdecreased adhesion is preferable, for example, because it increases thestrippability of the polymeric composition from other compositions towhich it is adhered. For example, decreased adhesion in the case ofelectrical cable allows for easier strippability of the semi-conductiveshield from an underlying insulating material.

Based on the instant disclosure, one skilled in the art will recognizethat the various components of the polymer compositions discussed abovemay be selected and adjusted as necessary to achieve specific endproducts with desirable performance characteristics. The invention willnow be described in more detail with reference to specific preferredembodiments thereof, it being understood that these examples areintended to be illustrative only, and the invention is not intended tobe limited to the materials, conditions, process parameters, etc.recited herein. All parts and percentages are by weight unless otherwiseindicated.

EXAMPLES Example 1

Polyethylene glycol-treated carbon black pellets are formed wherein thepolyethylene glycol is used as a pelletizing aid in producing the carbonblack pellets from carbon black in its fluffy form. In this example, thecarbon black has a dibutyl phthalate absorption number (DBP) of 138cc/100 g and an iodine surface area of 68 mg/g. Here, the DBP ismeasured according to ASTM D 2414 and the iodine surface area ismeasured according to ASTM D 1510. The carbon black is combined with anaqueous binder solution of polyethylene glycol (molecular weight=20,000)sufficient to yield a treated carbon black having 2% polyethylene glycolby weight of carbon black. The carbon black and aqueous binder solutionare mixed in a continuous pin pelletizer operating with a rotor speed of1,100 RPM and a mass flow rate ranging from 1,200 to 1,800 lbs/hr. Thepellets are then dried in a heated rotating drum to provide carbon blackpellets with a moisture content of below about 0.6%.

The thus-produced carbon black pellets are assessed for pellet strengthaccording to ASTM D 1937. The carbon black pellets are also assessed forpellet attrition using a modified version of ASTM D 4324, which ismodified to generate the level of dust after shaking samples of thecarbon black pellets for five and twenty minutes. The results of thesemeasurements are presented in Table 1 below.

Examples 2 and 3

Polyethylene glycol-treated carbon black pellets are prepared as inExample 1, except that the molecular weight of the polyethylene glycolcontained in the aqueous binder solution is 35,000 (Example 2) and100,000 (Example 3). The same pellet strength and pellet attritionmeasurements are made as in Example 1, and the results are presented inTable 1 below.

Comparative Example 1

Carbon black pellets are prepared according to Example 1, except thatthe binder solution consists only of water, i.e., does not containpolyethylene glycol. The same pellet strength and attrition measurementsare made as in Example 1, and the results are presented in Table 1below.

                  TABLE 1                                                         ______________________________________                                                                    Percent                                                                              Percent                                             Molecular                                                                              Pellet    Dust   Dust                                       Example  Weight of                                                                              Strength  After  After                                      #        PEG      (lbs)     5 Minutes                                                                            20 Minutes                                 ______________________________________                                        1        20,000   30.6      0.2    0.2                                        2        35,000   24.0      0.4    1.2                                        3        100,000  29.7      0.4    0.8                                        Comp 1   N/A      15.6      5.2    7.6                                        ______________________________________                                    

Example 4

A semi-conductive compound is produced using the polyethyleneglycol-treated carbon black pellets produced in Example 1 above. Thecarbon black pellets are compounded with an ethylene vinyl acetate resinusing a ZSK twin screw extruder. The ethylene vinyl acetate resin has amelt index of 3 and contains 40% vinyl acetate by weight. The resultantcompound is evaluated for melt viscosity (at a shear rate of 50 s⁻¹) andfor microscopic dispersion of the carbon black. The microscopicdispersion of carbon black is evaluated by examining an extruded tape ofthe semi-conductive compound for surface imperfections with an opticalmicroscope and a reflective light source. The area of the imperfectionassigned to undispersed carbon black is related to the total area oftape examined. In this measurement, particles of dust and gel polymerare excluded. The results of these measurements are presented in Table 2below.

Examples 5 and 6 and Comparative Example 2

Semi-conductive materials are prepared as in Example 4, incorporatingthe carbon black pellets from Examples 2 and 3 and comparative Example1, to produce semi-conductive compounds for Examples 5 and 6 andcomparative Example 2, respectively. The same measurements of meltviscosity and microscopic dispersion are made as in Example 4. Theresults are presented in Table 2 below.

                  TABLE 2                                                         ______________________________________                                                                       Undispersed                                              Carbon Black                                                                              Viscosity                                                                              Carbon Black                                   Example # Pellets     Pa-sec   %                                              ______________________________________                                        4         Example 1   4,613    0.0175                                         5         Example 2   4,679    0.0083                                         6         Example 3   6,275    0.0186                                         Comp 2    Comparative 1                                                                             6,078    0.047                                          ______________________________________                                    

Example 7

The semi-conductive compound of Example 4 is evaluated for strippabilityonto a crosslinked polyethylene insulation compound. Into thesemi-conductive compound of Example 4 is introduced 1% by weight ofdicumyl peroxide, using a Brabender mixer. The temperature duringprocessing is maintained below 150° C. to minimize decomposition of theperoxide. The material is then transferred to a heated hydraulic press,maintained at a temperature of 130° C., and plaques of 1.2 mm inthickness are produced. Plaques of polyethylene having a thickness of 2mm and containing 1% dicumyl peroxide are also prepared in a similarmanner. The two plaques are then laminated together under a pressure of100 psi and exposed to a curing cycle of 180° C. for fifteen minutes.The bonded laminates are allowed to cool to a temperature below 100° C.under pressure. The delamination force under a peeling angle of 180degrees and a separation speed of 3.94 inches/minute is recorded. Thetests are conducted twenty-eight times, and the average peel force isprovided in Table 3 below.

Examples 8 and 9 and Comparative Example 3

Similar to Example 7, Examples 8 and 9 and comparative Example 3evaluate the strippability onto a crosslinked polyethylene insulationcompound of the semi-conductive compounds produced in Examples 5 and 6and comparative Example 2, respectively. The average peel force for eachof the materials is presented in Table 3 below.

                  TABLE 3                                                         ______________________________________                                                      Conductive Peel Force                                           Example #     Composition                                                                              lb/0.5 in. width                                     ______________________________________                                        Example 7     Example 4  4.46 ± 0.20                                       Example 8     Example 5  4.46 ± 0.14                                       Example 9     Example 6  4.39 ± 0.18                                       Comparative 3 Comparative 2                                                                            6.55 ± 0.46                                       ______________________________________                                    

Example 10

Polyethylene glycol-treated carbon black pellets are formed wherein thepolyethylene glycol is used as a pelletizing aid in producing the carbonblack pellets from carbon black in its fluffy form. In this example, thecarbon black has a DBP of 143 cc/100 g and an iodine surface area of 129mg/g. The carbon black is combined with an aqueous binder solution ofpolyethylene glycol (molecular weight=1,000) sufficient to yield atreated carbon black having 2% polyethylene glycol by weight of carbonblack. The carbon black and aqueous binder solution are mixed in acontinuous pin pelletizer operating with a rotor speed of 1,000 RPM anda mass flow rate of 850 lbs/hr. The pellets are collected and dried in aheated air circulating oven held at a temperature of 125° C. until themoisture content is reduced to below about 0.5%.

The thus-produced carbon black pellets are assessed for pellet strengthand attrition resistance as described above. The results of thesemeasurements are presented in Table 4 below.

Examples 11-14

Polyethylene glycol-treated carbon black pellets are prepared as inExample 10, except that the molecular weight of the polyethylene glycolcontained in the aqueous binder solution is 8,000 (Example 11), 20,000(Example 12), 35,000 (Example 13) and 100,000 (Example 14). In the caseof Example 14, the binder solution contains the polyethylene glycol inan amount sufficient to yield a treated carbon black having 1%polyethylene glycol by weight of carbon black. The same pellet strengthand pellet attrition measurements are made as in Example 10, and theresults are presented in Table 4 below.

Comparative Example 4

Carbon black pellets are prepared according to Example 10, except thatthe binder solution consists only of water, i.e., does not containpolyethylene glycol. The same pellet strength and attrition measurementsare made as in Example 10, and the results are presented in Table 4below.

                  TABLE 4                                                         ______________________________________                                                Molecular Pellet   Percent Dust                                                                           Percent Dust                              Example Weight of Strength After    After                                     #       PEG       (lbs)    5 Minutes                                                                              20 Minutes                                ______________________________________                                        10      1,000     63.3     0.7      1.0                                       11      8,000     55.3     0.7      1.4                                       12      20,000    82.0     0.6      2.3                                       13      35,000    67.1     0.1      0.2                                       14      100,000   50.5     0.6      0.9                                       Comp 4  N/A       44.1     2.9      9.6                                       ______________________________________                                    

Example 15

Semi-conductive compounds are produced using the polyethyleneglycol-treated carbon black pellets produced in Example 10 above. Thecarbon black pellets are individually compounded with three differentpolymers using a Brabender mixer. The compounds contain 40% carbon blackand 60% polymer by weight. The three polymers are (1) an ethylene vinylacetate copolymer containing 40% vinyl acetate and having a melt indexof 3; (2) an ethylene vinyl acetate copolymer containing 18% vinylacetate and having a melt index of 2.5; and (3) an ethylene ethylacrylate copolymer containing 18% ethyl acrylate and having a melt indexof 3.4. The resultant compounds are evaluated for melt viscosity (at ashear rate of 50 s⁻¹ and 130° C.), as described above. The results ofthese measurements are presented in Table 5 below.

Examples 16-19 and Comparative Example 5

Semi-conductive materials are prepared as in Example 15, incorporatingthe carbon black pellets from Examples 11-14 and comparative Example 4,to produce semi-conductive compounds for Examples 16-19 and comparativeExample 5, respectively. The same measurements of melt viscosity aremade as in Example 15. The results are presented in Table 5 below.

                  TABLE 5                                                         ______________________________________                                                      Melt Viscosity                                                  Example  Carbon Black                                                                             Polymer    Polymer                                                                             Polymer                                  #        Pellets    1          2     3                                        ______________________________________                                        15       Example 10 8,007      2,930 2,711                                    16       Example 11 6,952      5,291 4,700                                    17       Example 12 7,171      5,990 5,203                                    18       Example 13 6,996      5,794 5,203                                    19       Example 14 8,004      6,537 5,706                                    Comp 5   Comparative 4                                                                            8,155      7,368 7,018                                    ______________________________________                                    

Additionally, all of Examples 15-19 show that an addition ofpolyethylene glycol to treat the carbon black results in an improvementin carbon black dispersion.

Examples 20-36 and Comparative Example 6

Carbon black compounds suitable for pigmentary ultra-violet protectionare prepared as follows.

Carbon black with a DBP of 145 cc/100 g and an iodine surface area of 70mg/g are pelletized with various aqueous solutions of varyingconcentrations of polyethylene glycol in a pin pelletizer operating witha rotor speed of 1,050 RPM. In the case of Comparative Example 6, thecarbon black is pelletized with a 100% aqueous solution, without anypolyethylene glycol. The pellets are collected and dried in a heated aircirculating oven held at a temperature of 125° C. until the moisturecontent is reduced to below about 0.5%. The pellets are evaluated forpellet strength according to ASTM D 1937 and pellet attrition accordingto the modified version of ASTM D 4324, as in Example 1. The results arepresented in Table 6.

Several of the carbon black pellets are then compounded with low densitypolyethylene, having a melt index of 26, to produce a 40% pigmentmasterbatch. The polyethylene compounds are then assessed for meltviscosity at 130° C. and a shear rate of 50 s⁻¹. The results arepresented in Table 6.

                  TABLE 6                                                         ______________________________________                                                                     Percent                                          Molecular   %        Pellet  Dust     Melt                                    Example                                                                              Weight of                                                                              Content  Strength                                                                            5    10    Viscosity                           #      PEG      PEG      (lbs) Min. Min.  (Pa)                                ______________________________________                                        Comp 6 N/A      0.0      44.1  2.9  9.6   5,116                               20     1,000    0.5      69.1  0.70 1.42                                      21     1,000    1.0      70.7  0.26 1.04                                      22     1,000    2.0      55.3  0.74 1.38  2,908                               23     1,000    4.0      72.1  0.44 0.50                                      24     8,000    0.5      69.1  0.70 1.42                                      25     8,000    1.0      70.7  0.26 1.04                                      26     8,000    2.0      47.3  1.04 2.54  3,673                               27     20,000   0.5      72.0  0.26 0.58                                      28     20,000   1.0      78.9  0.26 0.34                                      29     20,000   2.0      82.0  0.62 2.26  3,341                               30     20,000   4.0      133.5 0.20 1.20                                      31     35,000   0.5      66.0  0.34 0.72  5,004                               32     35,000   1.0      63.6  0.36 1.78  3,784                               33     35,000   2.0      67.1  0.08 0.18  3,341                               34     35,000   4.0      75.2  0.12 0.14                                      35     100,000  0.5      66.3  0.34 0.54                                      36     100,000  1.0      55.0  0.36 0.60  3,027                               ______________________________________                                    

In all of Examples 20-36, the incorporation of polyethylene glycolcontributes to improved pellet strength and higher attrition resistance.The results also appear to be independent of the molecular weight of thepolyethylene glycol. The viscosity of the carbon black masterbatch isalso lowered by the incorporation of polyethylene glycol as a bindermaterial. The polyethylene glycol also allows for easier incorporationinto an extruder film or profile where the final carbon blackconcentration is in the range of 0.5% to 4.0% depending on the finalapplication.

Furthermore, samples of a composition with a 2.5% carbon black loadingin low density polyethylene (LDPE) having a melt index of 0.7 areprepared to simulate a film application. A visual inspection of thesamples indicate qualitatively an improvement in carbon blackdispersion.

Examples 37-38 and Comparative Example 7

Carbon black compounds suitable for use as masterbatches are prepared.

Carbon black with a DBP of 135 cc/100 g and an iodine surface area of180 mg/g are pelletized with various aqueous solutions of varyingconcentrations of polyethylene glycol in a pin pelletizer operating witha rotor speed of 1,100 RPM. The aqueous solutions of Examples 37 and 38include polyethylene glycol (MW=35,000) sufficient to provide levels inthe carbon black pellets of 2% and 16%, respectively. ComparativeExample 7 uses a 100% aqueous solution. The pellets are collected anddried in a heated air circulating oven held at a temperature of 125° C.until the moisture content is reduced to below about 0.3%.

The dry carbon black pellets are then compounded with low densitypolyethylene, having a melt index of 26, to produce a masterbatchcontaining 40% carbon black by weight. The carbon black pellets and lowdensity polyethylene are mixed in a Brabender mixer with an initialtemperature of 115° C. and speed of 50 RPM. The polyethylene compoundsare then measured for melt viscosity at 130° C. and a shear rate of 50s⁻¹. The results are presented in Table 7.

                  TABLE 7                                                         ______________________________________                                               Pellet                                                                        Strength                                                                            Percent Dust   Melt Viscosity                                    Example #                                                                              (lbs)   5 Min.     10 Min.                                                                             (Pa)                                        ______________________________________                                        Comp 7   44      3.6        15.0  4,330                                       37       101     0.3        1.5   3.913                                       38       158     0.1        0.4   4,320                                       ______________________________________                                    

Examples 39-40 and Comparative Example 8

Compounds are prepared according to Examples 37-38 and ComparativeExample 7, except that the carbon black feedstock has a DBP of 136cc/100 g and an iodine surface area of 120 mg/g. The same masterbatchcompositions are prepared and tested, with the results presented inTable 8.

                  TABLE 8                                                         ______________________________________                                               Pellet                                                                        Strength                                                                            Percent Dust   Melt Viscosity                                    Example #                                                                              (lbs)   5 Min.     10 Min.                                                                             (Pa)                                        ______________________________________                                        Comp 8   61.9    0.8        5.2   4,591                                       39       133     0.1        0.3   3,804                                       40       157     0.05       0.12  2,689                                       ______________________________________                                    

Examples 41-45

Polyethylene glycol treated carbon blacks are prepared as described inExample 1 above. The treated carbon blacks are prepared by using varyingamounts of polyethylene glycol as a treating compound for the carbonblack. Specifically, five carbon blacks are prepared using the followingtypes and amounts of polyethylene glycol as a treating compound.

    ______________________________________                                        Carbon     Polyethylene Glycol                                                                        Parts by Weight                                       Black #    Molecular Weight                                                                           of Carbon Black                                       ______________________________________                                        1          20,000       2.0                                                   2          20,000       4.0                                                   3          35,000       2.0                                                   4          35,000       3.0                                                   5          100,000      2.0                                                   ______________________________________                                    

Here it is also noted that the 100,000 molecular weight polyethyleneglycol is also known as a polyethylene oxide compound.

Semi-conductive shields for use in preparing electrical cables areprepared by combining approximately 57 parts by weight of anethylene/1-butene copolymer (15% butene content), about 41 parts byweight of one of the treated carbon blacks and about 1.5 parts by weightof other additives. The ethylene/1-butene copolymer has a melt index of27, a density of 0.9 g/cm³ and a molecular weight distribution (MWD) of2.15. The additives include about 0.5% of any antioxidant (such as1,2-dihydro-2,2,4-trimethylquinoline, octadecyl3,5-ditert-butyl-4-hydroxyhydrocinnamate or a mixture thereof) and 1.0%of an organic peroxide curativeα,α'-bis(tert-butylperoxy)-diisopropylbenzene. The specific componentratios are as follows:

    ______________________________________                                        Component 41       42      43     44    45                                    ______________________________________                                        Ethylene/1-butene                                                                       57.55    56.73   57.55  57.14 57.55                                 Carbon Black #1                                                                         40.95    --      --     --    --                                    Carbon Black #2                                                                         --       41.77   --     --    --                                    Carbon Black #3                                                                         --       --      40.95  --    --                                    Carbon Black #4                                                                         --       --      --     41.36 --                                    Carbon Black #5                                                                         --       --      --     --    40.95                                 Antioxidant                                                                              0.50     0.50    0.50   0.50  0.50                                 Peroxide Curative                                                                        1.00     1.00    1.00   1.00  1.00                                 Total     100.00   100.00  100.00 100.00                                                                              100.00                                ______________________________________                                    

The components are mixed in a Banbury mixer or other suitable equipment.

The formulations are tested for various physical and electricalcharacteristics. Cure data is determined by measuring the torque(lb-in.) on plaques of the formulation with an Oscillating DiscRheometer (ODR) operating to 400° F. and 3° arc. The low (M_(l)) andhigh (M_(h)) ODR torque values, scorch time (t_(s) 2) and 50% (t_(c)(50)) and 90% (t_(c) (⁹⁰)) cure times are presented in Table 10 below.The formulation is also evaluated for volume resistivity at varioustemperatures, tensile strength and elongation, and extrusion parameterson a Haake Rheocord. The results are presented in Table 9 below.

Comparative Examples 9-13

Semi-conductive shields for use in preparing electrical cables areprepared similar to those in Examples 41-45 above, except that thecarbon black is an untreated carbon black. That is, the carbon blackpellets are derived from carbon black pelletized with deionized water.

Semi-conductive shields for use in preparing electrical cables areprepared by combining approximately 57 parts by weight of anethylene/1-butene copolymer (the same copolymer as used in Examples41-45), about 41 parts by weight of the untreated carbon black, andabout 1.5 parts by weight of other additives. The formulationadditionally includes polyethylene glycol (PEG) added directly into theformulation. In these Comparative Examples, varying amounts of differingmolecular weight polyethylene glycol are added to the formulations. Thespecific component ratios are as follows:

    ______________________________________                                                   Comp    Comp     Comp  Comp   Comp                                 Component  9       10       11    12     13                                   ______________________________________                                        Carbon Black                                                                             40.13   40.13    40.13 40.13  40.13                                Ethylene/1-butene                                                                        57.55   56.73    57.55 56.73  57.55                                20,000 MW PEG                                                                             0.82   --       --    --     --                                   20,000 MW PEG                                                                            --      1.64     --    --     --                                   35,000 MW PEG                                                                            --      --        0.82 --     --                                   35,000 MW PEG                                                                            --      --       --    1.64   --                                   100,000 MW PEG                                                                           --      --       --    --      0.82                                Antioxidant                                                                               0.50   0.50      0.50 0.50    0.50                                Peroxide Curative                                                                         1.00   1.00      1.00 1.00    1.00                                Total      100.00  100.00   100.00                                                                              100.00 100.00                               ______________________________________                                    

Here, all of the parts by weight are based on the weight of the totalformulation. The components are mixed in a Banbury mixer or othersuitable equipment as in Examples 41-45 above.

It is also noted here that the additives in Comparative Examples 9-13are the same as those in Examples 41-45, and are present in the sameamounts. Additionally, the amounts of polymer, carbon black andpolyethylene glycol are the same in Examples 41-43 and 45, andComparative Examples 9-11 and 13, respectively. It should be noted thatin Example 44, the amount of polyethylene glycol used is 3% by weight ofthe carbon black and is used as a treating compound on the carbon black.Comparative Example 12 contains polyethylene glycol in an amount of 4%by weight of the carbon black and is added directly into theformulation. Furthermore, as noted above, the polyethylene glycol inExamples 41-45 is used to treat the carbon black, whereas in ComparativeExamples 9-13 it is added directly to the formulation.

The same tests and measurements are conducted as in Examples 41-45, andthe results are presented in Table 9.

                                      TABLE 9                                     __________________________________________________________________________                  41  42  43  44  45  Comp 9                                                                            Comp 10                                                                            Comp 11                                                                            Comp 12                                                                            Comp                     __________________________________________________________________________                                                         13                       ODR Measurements at 400° F.                                            M.sub.1, lb-in.                                                                             2.2 2.0 2.0 2.0 2.0 2.3 2.8  2.1  2.6  2.2                      M.sub.h, lb-in.                                                                             67.2                                                                              60.3                                                                              66.5                                                                              70.5                                                                              65.0                                                                              69.9                                                                              70.1 69.1 65.1 69.8                     t.sub.s 2, sec.                                                                             55.3                                                                              54  57  54  52  59.7                                                                              53.6 56.6 52.3 50.3                     t.sub.c (50), sec.                                                                          108.3                                                                             108 114 108 105 111 101.3                                                                              106  100.3                                                                              99                       t.sub.c (90), sec.                                                                          160.3                                                                             167 173.7                                                                             162.3                                                                             149 157.7                                                                             146.3                                                                              149.3                                                                              146.6                                                                              143.7                    Volume Resistivity, ohm-cm                                                    Room Temperature                                                                            5   7   6   5   5   5   4    4    4    4                        50° C. 7   9   7   7   6   6   6    5    5    6                        90° C. 30  41  30  30  26  28  22   21   18   24                       110° C.                                                                              35  48  35  35  31  31  24   27   19   27                       130° C.                                                                              37  50  38  38  33  35  26   32   21   30                       Extrusion Parameters                                                          20 RPM Head Pressure, psi                                                                   1306                                                                              945 1108                                                                              1505                                                                              1115                                                                              1201                                                                              1156 1268 1564 1503                     20 RPM HP/Output, psi/g/min.                                                                79.9                                                                              58.3                                                                              65.2                                                                              100.4                                                                             69.2                                                                              78.0                                                                              72.9 77.8 97.3 92.2                     30 RPM Head Pressure, psi                                                                   1501                                                                              1141                                                                              1345                                                                              1877                                                                              1357                                                                              1429                                                                              1402 1550 1903 1685                     30 RPM HP/Output, psi/g/min.                                                                60.0                                                                              48.0                                                                              53.4                                                                              81.3                                                                              54.6                                                                              62.6                                                                              57.8 62.9 77.9 67.5                     40 RPM Head Pressure, psi                                                                   1580                                                                              1356                                                                              1551                                                                              2184                                                                              1568                                                                              1680                                                                              1625 1767 2203 1770                     40 RPM HP/Output, psi/g/min.                                                                47.3                                                                              40.7                                                                              45.8                                                                              71.3                                                                              47.3                                                                              53.2                                                                              48.8 54.0 67.6 55.6                     Tensile Strength and Elongation                                               Initial Conditions                                                            Avg Tensile Strength, psi                                                                   3426                                                                              3286                                                                              3325                                                                              3332                                                                              3329                                                                              3364                                                                              3282 3322 3239 3424                     Average Elongation, %                                                                       240 257 229 219 208 245 224  234  242  242                      Average 100% Modulus                                                                        2515                                                                              2340                                                                              2488                                                                              2511                                                                              2500                                                                              2454                                                                              2433 2455 2382 2467                     Average 200% Modulus                                                                        3241                                                                              3040                                                                              3194                                                                              3241                                                                              3156                                                                              3166                                                                              3130 3162 3056 3214                     After aging at 121° C.                                                 Avg Tensile Strength, psi                                                                   3245                                                                              3204                                                                              3177                                                                              2952                                                                              3255                                                                              3092                                                                              3127 3099 2960 3175                     Average Elongation, %                                                                       234 267 191 203 253 249 238  242  233  234                      Tensile Retention, %                                                                        95  98  96  89  98  92  95   94   91   93                       Elongation Retention, %                                                                     97  104 83  93  121 101 106  103  96   97                       __________________________________________________________________________

Examples 46-50

Semi-conductive shields for use in preparing electrical cables areprepared by combining approximately 48 parts by weight of anethylene/vinyl acetate copolymer (50% vinyl acetate content), about11.08 parts by weight of an ethylene/octene copolymer, about 37 parts byweight of one of the treated carbon blacks prepared for Examples 41-45above, and about 3.5 parts by weight of other additives. Theethylene/vinyl acetate copolymer has a melt index of between 7 and 11.The ethylene/octene copolymer has a melt index of 31 and a density of0.87 g/cm³. The additives include about 0.9% of a stearic acidprocessing aid, 0.7% of an antioxidant1,2-dihydro-2,2,4-trimethylquinoline, 1.0% of an organic peroxidecurative α,α'-bis(tert-butylperoxy)-diisopropylbenzene and 0.9%hydrotalcite. The specific component ratios are as follows:

    ______________________________________                                        Component    46      47      48    49    50                                   ______________________________________                                        Ethylene/vinyl acetate                                                                     48.22   47.40   48.22 47.81 48.22                                Carbon Black #1                                                                            37.20   --      --    --    --                                   Carbon Black #2                                                                            --      38.02   --    --    --                                   Carbon Black #3                                                                            --      --      37.20 --    --                                   Carbon Black #4                                                                            --      --      --    37.61 --                                   Carbon Black #5                                                                            --      --      --    --    37.20                                Ethylene/octene Polymer                                                                    11.08   11.08   11.08 11.08 11.08                                Antioxidant   0.70    0.70    0.70  0.70  0.70                                Stearic Acid  0.90    0.90    0.90  0.90  0.90                                Hydrotalcite  0.90    0.90    0.90  0.90  0.90                                Peroxide Curative                                                                           1.00    1.00    1.00  1.00  1.00                                Total        100.00  100.00  100.00                                                                              100.00                                                                              100.00                               ______________________________________                                    

The components are mixed in a Banbury mixer.

The same tests and measurements are conducted as in Examples 41-45, andthe results are presented in Table 10. Additionally, the formulationsare tested for adhesion to crosslinked polyethylene, and the results arealso presented in Table 10.

Comparative Examples 14-18

Semi-conductive shields for use in preparing electrical cables areprepared similar to those in Examples 46-50 above, except that thecarbon black is an untreated carbon black. That is, the carbon blackpellets are derived from carbon black pelletized with deionized water.

Semi-conductive shields for use in preparing electrical cables areprepared by combining approximately 48 parts by weight of theethylene/vinyl acetate copolymer (50% vinyl acetate content) and about11 parts by weight of the ethylene/octene copolymer both as used inExamples 46-50, about 37 parts by weight of the untreated carbon black,and about 3.5 parts by weight of other additives. The formulationadditionally includes polyethylene glycol (PEG) added directly into theformulation. In these Comparative Examples, varying amounts of differingmolecular weight polyethylene glycol are added to the formulations. Thespecific component ratios are as follows:

    ______________________________________                                                     Comp    Comp    Comp  Comp  Comp                                 Component    14      15      16    17    18                                   ______________________________________                                        Carbon Black 36.38   36.38   36.38 36.38 36.38                                Ethylene/vinyl acetate                                                                     48.22   47.56   48.22 47.56 48.22                                20,000 MW PEG                                                                               0.82   --      --    --    --                                   20,000 MW PEG                                                                              --       1.64   --    --    --                                   35,000 MW PEG                                                                              --      --       0.82 --    --                                   35,000 MW PEG                                                                              --      --      --     1.64 --                                   100,000 MW PEG                                                                             --      --      --    --     0.82                                Ethylene/octene Polymer                                                                    11.08   10.92   11.08 10.92 11.08                                Antioxidant   0.70    0.70    0.70  0.70  0.70                                Stearic Acid  0.90    0.90    0.90  0.90  0.90                                Hydrotalcite  0.90    0.90    0.90  0.90  0.90                                Peroxide Curative                                                                           1.00    1.00    1.00  1.00  1.00                                Total        100.00  100.00  100.00                                                                              100.00                                                                              100.00                               ______________________________________                                    

Here, all of the parts by weight are based on the weight of the totalformulation. The components are mixed in a Banbury mixer as in Examples46-50 above.

It is also noted here that the additives in Comparative Examples 14-18are the same as those in Examples 46-50, and are present in the sameamounts. Additionally, the amounts of polymer, carbon black andpolyethylene glycol are the same in Examples 46-48 and 50, andComparative Examples 14-16 and 18, respectively. As between Example 49and Comparative Example 17, the difference is that the amount ofpolyethylene glycol used in Example 49 is 3% by weight of the carbonblack (and is used to treat the carbon black), but in ComparativeExample 17 4% polyethylene glycol by weight of carbon black is used as adirect additive into the formulation. Furthermore, as noted above, thepolyethylene glycol in Examples 46-50 is used to treat the carbon black,whereas in Comparative Examples 14-18 it is added directly to theformulation.

The same tests and measurements are conducted as in Examples 46-50, andthe results are presented in Table 10.

                                      TABLE 10                                    __________________________________________________________________________                      46  47  48  49  50  Comp 14                                                                            Comp 15                                                                            Comp 16                                                                            Comp                                                                               Comp                __________________________________________________________________________                                                              18                  ODR Measurements at 400° F.                                            M.sub.1, lb-in.   6.3 6.3 6.0 4.7 6.7 6.3  6.3  6.7  6.4  6.3                 M.sub.h, lb-in.   49.7                                                                              40.0                                                                              49.3                                                                              40.1                                                                              53.0                                                                              46.6 44.3 45.6 45.1 46.6                t.sub.s 2, sec.   49  48.7                                                                              52  55.7                                                                              49  43.3 43.6 52.6 46.3 47.7                t.sub.c (50), sec.                                                                              97.7                                                                              88  96  102 91  83.6 82.3 93.6 84   87                  t.sub.c (90), sec.                                                                              140.7                                                                             136 148 154.7                                                                             141 125  123.3                                                                              141  123.3                                                                              129.3               Adhesion to Crosslinked Polyethylene,                                         lb/1/2 in.                                                                    Room Temperature  3.89                                                                              4.25                                                                              3.47                                                                              3.08                                                                              4.45                                                                              5.56 5.2  5.06 4.11 8.37                Volume Resistivity, ohm-cm                                                    Room Temperature  305 399 400 476 240 611  803  719  525  653                 50° C.     359 464 466 563 307 454  566  618  459  944                 90° C.     271 348 346 447 217 492  600  650  452  583                 110° C.    240 307 310 412 193 399  481  529  367  508                 130° C.    201 261 267 363 165 376  454  513  347  435                 Extrusion Parameters                                                          20 RPM Head Pressure, psi                                                                       1718                                                                              1615                                                                              1516                                                                              1653                                                                              1515                                                                              1762 1735 1666 1669 1560                20 RPM HP/Output, psi/g/min.                                                                    115.8                                                                             108.6                                                                             115.5                                                                             134.0                                                                             112.0                                                                             145.9                                                                              122.7                                                                              118.8                                                                              118.9                                                                              120.5               30 RPM Head Pressure, psi                                                                       2138                                                                              2030                                                                              1895                                                                              2101                                                                              1855                                                                              2197 2050 2031 2046 N/A                 30 RPM HP/Output, psi/g/min.                                                                    90.1                                                                              85.7                                                                              92.8                                                                              101.1                                                                             89.0                                                                              109.8                                                                              100.5                                                                              98.6 93.4 N/A                 40 RPM Head Pressure, psi                                                                       2404                                                                              2247                                                                              2203                                                                              2381                                                                              2234                                                                              2476 2431 2279 2332 2278                40 RPM HP/Output, psi/g/min                                                                     80.7                                                                              74.9                                                                              83.0                                                                              83.9                                                                              74.9                                                                              88.4 83.0 86.3 79.6 78.8                Tensile Strength and Elongation                                               Initial Conditions                                                            Avg Tensile Strength, psi                                                                       2134                                                                              2079                                                                              2113                                                                              2262                                                                              2179                                                                              2099 2120 2167 2066 2140                Average Elongation, %                                                                           245 240 239 236 243 263  277  269  251  268                 Average 100% Modulus                                                                            1177                                                                              1117                                                                              1152                                                                              1269                                                                              1190                                                                              1069 1035 1078 1082 1050                Average 200% Modulus                                                                            1964                                                                              1909                                                                              1953                                                                              2116                                                                              1998                                                                              1867 1856 1908 1872 1883                After aging at 121° C.                                                 Avg Tensile Strength, psi                                                                       2072                                                                              2065                                                                              2163                                                                              2155                                                                              2129                                                                              2066 1988 2059 1945 2084                Average Elongation, %                                                                           248 264 263 247 249 284  274  275  300  278                 Tensile Retention, %                                                                            97  99  102 95  98  98   94   95   94   97                  Elongation Retention, %                                                                         101 110 110 105 103 108  99   102  119  104                 __________________________________________________________________________

Comparative Examples 19-20

Further polymer compositions are prepared to compare the resultsobtained in the above Examples and Comparative Examples with polymerformulations not including the polyethylene glycol compound as either apelletizing aid for treating the carbon black or as a direct additive.

A semi-conductive formulation is prepared as in Comparative Examples9-13 except that the formulation contains approximately 58 parts byweight of an ethylene/1-butene copolymer (the same copolymer as used inExamples 41-45), about 40.5 parts by weight of the untreated carbonblack, and about 1.5 parts by weight of the other additives. Theformulation is denoted Comparative Example 19.

The additives in Comparative Example 19 are the same as those inExamples 41-45 and Comparative Examples 9-13 and are present inapproximately the same amounts, except for the exclusion of thepolyethylene glycol compound.

A further semi-conductive formulation is prepared as in ComparativeExamples 14-18 except that the formulation contains approximately 48.9parts by weight of the ethylene/vinyl acetate copolymer (50% vinylacetate content) and 11.24 parts by weight of the ethylene/octenecopolymer used in Examples 46-50, about 36.4 parts by weight of theuntreated carbon black, and about 3.5 parts by weight of otheradditives. The formulation is denoted Comparative Example 20.

The additives in Comparative Example 20 are the same as those inExamples 46-50 and Comparative Examples 14-18 and are present inapproximately the same amounts, except for the exclusion of thepolyethylene glycol compound.

The components for each formulation are mixed in a Banbury mixer orother suitable equipment as in Examples 41-45 above. The formulationsare then tested and measured as in Examples 41-45, and the results arepresented in Table 11.

For ease of comparison, the results of Comparative Examples 9 and 14 andExamples 41 and 46 are reproduced in Table 11. Table 11 thus shows theresults for the two different polymer formulations containing nopolyethylene glycol (Comparative Examples 19 and 20), formulationscontaining polyethylene glycol in an amount of 2% by weight of carbonblack as a direct additive to the formulations (Comparative Examples 9and 14), and formulations containing polyethylene glycol in an amount of2% by weight of carbon black as a treating agent for the carbon black(Examples 41 and 46).

                  TABLE 11                                                        ______________________________________                                                 Comp  Comp           Comp  Comp                                               19    9       41     20    14    46                                  ______________________________________                                        ODR Measurements at 400° F.                                            M.sub.1, lb-in.                                                                          2.0     2.3     2.2  6.8   6.3   6.3                               M.sub.b, lb-in.                                                                          72.7    69.9    67.2 47.1  46.6  49.7                              t.sub.c 2, sec.                                                                          61      59.7    55.3 51    43.3  49                                t.sub.c (50), sec.                                                                       122     111     108.3                                                                              98.7  83.6  97.7                              t.sub.c (90), sec.                                                                       181     157.7   160.3                                                                              150.7 125   140.7                             Adhesion to Crosslinked Polyethylene, lb/1/2 in.                              Room Temperature                                                                         NA      NA      NA   4.51  5.56  3.89                              Volume Resistivity, ohm-cm                                                    Room Temperature                                                                         5       5       5    811   611   305                               50° C.                                                                            7       6       7    961   454   359                               90° C.                                                                            28      28      30   721   492   271                               110° C.                                                                           34      31      35   653   399   240                               130° C.                                                                           37      35      37   556   376   201                               Viscosity and Shear Measurements                                              20 RPM Head                                                                              1573    1201    1306 1928  1762  1718                              Pressure. psi                                                                 20 RPM HP/Output,                                                                        105.8   78.0    79.9 156.3 145.9 115.8                             psi/g/min.                                                                    30 RPM Head                                                                              2006    1429    1501 2290  2197  2138                              Pressure, psi                                                                 30 RPM HP/Output,                                                                        86.8    62.6    60.0 119.1 109.8 90.1                              psi/g/min.                                                                    40 RPM Head                                                                              2337    1680    1580 2723  2476  2404                              Pressure, psi                                                                 40 RPM HP/Output,                                                                        76.3    53.2    47.3 99.3  88.4  80.7                              psi/g/min.                                                                    Tensile Strength and Elongation                                               Initial Conditions                                                            Avg Tensile                                                                              3324    3364    3426 2138  2099  2134                              Strength, psi                                                                 Average Elon-                                                                            231     245     240  254   263   245                               gation, %                                                                     Average 100%                                                                             2511    2454    2515 1254  1069  1177                              Modulus                                                                       Average 200%                                                                             3194    3166    3241 1997  1867  1964                              Modulus                                                                       After aging at 121° C.                                                 Avg Tensile                                                                              3072    3092    3245 2028  2066  2072                              Strength, psi                                                                 Average Elon-                                                                            212     249     234  228   284   248                               gation, %                                                                     Tensile    92      92      95   95    98    97                                Retention, %                                                                  Elongation 92      101     97   90    108   101                               Retention, %                                                                  ______________________________________                                    

The foregoing embodiments are intended to illustrate and not limit thepresent invention. It will be apparent that various modifications can bemade without departing from the spirit and scope of the invention asdefined by the appended claims.

What is claimed is:
 1. A treated carbon black comprising carbon blacktreated with at least one polyethylene glycol having a weight averagemolecular weight of from about 1,000 to about 20,000, wherein saidtreated carbon black is in a pelletized form.
 2. A treated carbon blackaccording to claim 1, wherein said polyethylene glycol is present in anamount of from about 0.1% to about 50% by weight of said carbon black.3. A treated carbon black according to claim 1, wherein saidpolyethylene glycol is present in an amount of from about 0.1% to about20% by weight of said carbon black.
 4. A treated carbon black accordingto claim 1, wherein said polyethylene glycol is present in an amount offrom about 1% to about 10% by weight of said carbon black.
 5. A treatedcarbon black comprising carbon black treated with at least onepolyethylene glycol having a weight average molecular weight of fromabout 100,000 to about 1,000,000.
 6. A process for preparing a treatedcarbon black, comprising treating a carbon black with at least onepolyethylene glycol having a weight average molecular weight of fromabout 1,000 to about 20,000, to produce the treated carbon black,wherein said treated carbon black is in a pelletized form.
 7. A processaccording to claim 6, wherein said polyethylene glycol is present in anamount of from about 0.1% to about 50% by weight of said treated carbonblack.
 8. A polymeric formulation comprising:at least one polymer and acarbon black treated with at least one polyethylene glycol having aweight average molecular weight of from about 1,000 to about 20,000,wherein said treated carbon black is in a pelletized form.
 9. Apolymeric formulation according to claim 8, wherein said polymer isselected from the group consisting of homopolymers, copolymers and graftpolymers of ethylene, elastomers of natural rubber, polybutadiene,polyisoprene, random styrene butadiene rubber, polychloroprene, nitrilerubbers, ethylene propylene copolymers and terpolymers, homopolymers andcopolymers of styrene, linear and branched polyether or polyesterpolyols, crystalline and amorphous polyesters and polyamides, alkydresins, rosin esters, rosin esters, hydrocarbon resins produced fromthermal or Friedal Crafts polymerization of cyclic diene monomers,ethylene/silane copolymers, ethylene/α-olefin/diene terpolymers, andmixtures thereof.
 10. A polymeric formulation according to claim 8,wherein said polymer is a polymer, copolymer or terpolymer containing atleast a polyolefin.
 11. A polymeric formulation comprising at least onepolymer and a carbon black treated with at least one polyethylene glycolhaving a weight average molecular weight of from about 100,000 to about1,000,000.
 12. A polymeric formulation comprising:at least one polymerand a carbon black treated with at least one polyethylene glycol havinga weight average molecular weight of from about 1,000 to about 20,000,wherein said polyethylene glycol is present in an amount of from about0.1% to about 50% by weight of said treated carbon black.
 13. Apolymeric formulation comprising:at least one polymer and a carbon blacktreated with at least one polyethylene glycol having a weight averagemolecular weight of from about 1,000 to about 20,000, wherein saidtreated carbon black is present in an amount of from about 0.1% to about65% by weight of said formulation.
 14. A polymeric formulation accordingto claim 12, further comprising at least one additive selected from thegroup consisting of crosslinking agents, vulcanizing agents,stabilizers, antioxidants, processing aids, pigments, dyes, colorants,metal deactivators, oil extenders, lubricants, and inorganic fillers.15. A polymeric formulation comprising at least one polymer and a carbonblack treated with at least one polyethylene glycol having a weightaverage molecular weight of from about 1,000 to about 20,000 or fromabout 100,000 to about 1,000,000, wherein said polymer is a copolymer ofethylene with at least one monomer selected from the group consisting ofvinyl acetate, C₁ -C₈ alkyl acrylates, C₁ -C₈ alkyl methacrylates, andalpha olefins, wherein said treated carbon black is in a pelletizedform.
 16. A polymeric formulation according to claim 15, wherein saidethylene copolymer is an ethylene/vinyl acetate copolymer containingvinyl acetate in an amount of from about 5 to about 80 mole percent. 17.A polymeric formulation according to claim 15, wherein said ethylenecopolymer is ethylene copolymerized with one of methyl acrylate, ethylacrylate or butyl acrylate.
 18. A polymeric formulation according toclaim 17, wherein said ethylene copolymer contains said one of methylacrylate, ethyl acrylate or butyl acrylate in an amount of from about 5to about 80 mole percent.
 19. A polymeric formulation according to claim15, wherein said ethylene copolymer is ethylene copolymerized with analpha olefin selected from the group consisting of propene, butene,hexene, and octene, said ethylene copolymer containing ethylene in anamount of from about 25 to about 98 mole percent.
 20. A polymericformulation according to claim 15, wherein said formulation comprisesfrom about 30 to about 80 parts by weight of said ethylene copolymer andfrom about 12 to about 50 parts by weight of said treated carbon black,based on the total weight of said formulation.
 21. A polymericformulation according to claim 20, wherein said treated carbon black isa carbon black treated with polyethylene glycol in an amount of fromabout 1% to about 10% by weight of said treated carbon black.
 22. Apolymeric formulation according to claim 20, further comprising at leastone additive selected from the group consisting of crosslinking agents,vulcanizing agents, stabilizers, antioxidants, processing aids,pigments, dyes, colorants, metal deactivators, oil extenders,lubricants, and inorganic fillers.
 23. A polymeric formulation accordingto claim 20, further comprising an ethylene/octene copolymer in anamount of from about 2% to about 30% by weight of said formulation. 24.A polymeric formulation according to claim 15, wherein said formulationcomprises from about 40 to about 90 parts by weight of an ethylene alphaolefin copolymer and from about 10 to about 50 parts by weight of saidtreated carbon black, based on the total weight of said formulation. 25.A polymeric formulation according to claim 24, wherein said ethylenealpha olefin copolymer is an ethylene butene copolymer.
 26. A polymericformulation according to claim 24, wherein said ethylene alpha olefincopolymer is an ethylene propylene copolymer.
 27. A polymericformulation according to claim 24, wherein said treated carbon black isa carbon black treated with polyethylene glycol in an amount of fromabout 1% to about 10% by weight of said treated carbon black.
 28. Apolymeric formulation according to claim 24, further comprising at leastone additive selected from the group consisting of crosslinking agents,vulcanizing agents, stabilizers, antioxidants, processing aids,pigments, dyes, colorants, metal deactivators, oil extenders,lubricants, and inorganic fillers.
 29. A shield for a power cablecomprising the polymeric formulation of claim 12, wherein saidformulation comprises said treated carbon black in an amount sufficientto impart semi-conductive properties to said formulation.
 30. A shieldfor a power cable comprising the polymeric formulation of claim 12,wherein said formulation comprises said treated carbon black in anamount sufficiently low so as not to impart conducting properties tosaid insulating material.
 31. A treated carbon black according to claim5, wherein said polyethylene glycol is present in an amount of fromabout 0.1% to about 50% by weight of said carbon black.
 32. A treatedcarbon black according to claim 5, wherein said polyethylene glycol ispresent in an amount of from about 0.1% to about 20% by weight of saidcarbon black.
 33. A treated carbon black according to claim 5, whereinsaid polyethylene glycol is present in an amount of from about 1% toabout 10% by weight of said carbon black.
 34. A treated carbon blackaccording to claim 5, wherein said treated carbon black is in apelletized form.
 35. A process for preparing a treated carbon black,comprising treating a carbon black with at least one polyethylene glycolhaving a weight average molecular weight of from about 100,000 to about1,000,000, to produce the treated carbon black.
 36. A process accordingto claim 35, wherein said polyethylene glycol is present in an amount offrom about 0.1% to about 50% by weight of said treated carbon black. 37.A polymeric formulation according to claim 11, wherein said polymer isselected from the group consisting of homopolymers, copolymers and graftpolymers of ethylene, elastomers of natural rubber, polybutadiene,polyisoprene, random styrene butadiene rubber, polychloroprene, nitrilerubbers, ethylene propylene copolymers and terpolymers, homopolymers andcopolymers of styrene, linear and branched polyether or polyesterpolyols, crystalline and amorphous polyesters and polyamides, alkydresins, hydrocarbon resins produced from thermal or Friedal Craftspolymerization of cyclic diene monomers, ethylene/silane copolymers,ethylene/α-olefin/diene terpolymers, and mixtures thereof.
 38. Apolymeric formulation according to claim 11, wherein said polymer is apolymer, copolymer or terpolymer containing at least a polyolefin.
 39. Apolymeric formulation according to claim 11, wherein said polyethyleneglycol is present in an amount of from about 0.1% to about 50% by weightof said treated carbon black.
 40. A polymeric formulation according toclaim 11, wherein said treated carbon black is present in an amount offrom about 0.1% to about 65% by weight of said formulation.
 41. Apolymeric formulation according to claim 11, further comprising at leastone additive selected from the group consisting of crosslinking agents,vulcanizing agents, stabilizers, antioxidants, processing aids,pigments, dyes, colorants, metal deactivators, oil extenders,lubricants, and inorganic fillers.
 42. The treated carbon blackaccording to claim 1, consisting essentially of said carbon blacktreated with said at least one polyethylene glycol having a weightaverage molecular weight of from about 1,000 to about 20,000.
 43. Theprocess for preparing a treated carbon black according to claim 6,consisting essentially of treating said carbon black with said at leastone polyethylene glycol having a weight average molecular weight of fromabout 1,000 to about 20,000, to produce the treated carbon black. 44.The polymeric formulation according to claim 8, wherein said carbonblack consists essentially of a carbon black treated with said at leastone polyethylene glycol having a weight average molecular weight of fromabout 1,000 to about 20,000.
 45. The treated carbon black according toclaim 1, wherein said at least one polyethylene glycol has a weightaverage molecular weight of from about 1,000 to about 10,000.
 46. Thetreated carbon black according to claim 1, wherein said at least onepolyethylene glycol has a weight average molecular weight of from about1,000 to about 8,000.